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UNITED STATES rxrnnrornicn. f-

LOUIS PLANER, OF NEW YORK, N. Y..

GROOVED PULLEY. p

Speccation of Letters Patent No. 26,707, dated JanuaryS, 1860.

`To all whom 'it may concern:

Similar letters of reference in the three views indicate correspondingparts.

The object of this invention is to arrange a grooved pulley in such amanner that it retains the belt perfectly tight when working in' onedirection, whereas when turned in the other direction it allows the beltto slip. l/Vith this object in view I have constructed my pulley withtangential ridges which extend from top to bottom on both sides of thegroove and which are so arranged, that the ridges on one side of thegroove stand exactly opposite to the spaces between the ridges 'on theother side. By this arrangement my pulley retains the belt exactly inthe same manner, as pulleys with radial ridges in their grooves, whenworking in one direction, but, when working in the other direction, thebelt is allowed to slip, and the turning of the pulley in the wrongdirection has no injurious influence on the machine, which it isintended to drive.

To enable those skilled in the art to make and use my invention, I willproceed to describe it.

The pulley A is constructed of two parts which are fastened together `bymeans of screws (i, but it may also be made o-f one piece if it isdesired. Each side of the groove b is furnished with sharp pointedridges c running tangentially from the outer circumference of the`pulley to` the circle forming the bottom ofthegroove andina directionopposite toftheydirection in which the pulley has to operate,1 and theyare so arranged, that those `on one" side ofl tl1`e1m50 groove standexactly opposite tothe spaces. n

between those on the` `other side, and theyl may be slightly curved as`clearly shownin]` f Fig. l. If the beltisnowplaced into fthe"` l groovequite loosely, the ridges on one; side .55?, g of the pulleyforce thesame intoithe spaces l between the ridges on the othersidefand if? l i astrain is exerted on thebelt inthe direc .y tion of the arrow, markedonuthe pulleyin .y Fig. l, the sharp edgesfof theridges bitevGO i intothe belt and retain itthe more tena-j.l l ciously, the strongerl thestrain `on. the"belt. i

On the other hand, if the strain on th b ltf; l is in the directionopposite `to `the arrow, i i marked on the pulley in `Figli 1, the sharp6al edges of theridges havelno; eifectonithe l same and it is allowedtoslipa` `This pulley@ is of particular advantage forsewingwzma chinesand for all such devices, where; a turn ing in the wrong directionhas aninjuriou y or disturbing influenceon the operation of@ the machine, andit mustiberemarked that; grooved pulleys with` `,radial ridges `cannotbe used in the same capacity iastheyretain@` the belt with equaltenacityinboth `direc-'1` 175` tions. H t I am awarethatvgrooved pulleyswith: radial ridges have been"l heretofore con-i. 1 structed; such I donot claim,\but1 y y Having thus fully described my invention f80 what Iclaim as new and desire to secure `by i l Letters Patent asa"`1iewgarticle ofmanufacture is: n .y f `fif n; A groovedpulleyAarranGedwithftanel 1 gential ridges c on the sideso the groove 83 as and for the purpose specifie`\d.`` i y 3 LOUISILANElt;fp"` n. j

Witnesses:

J. AUGUST HAssLnN, TH. BELL. p

